FED-STD-141 Paint, Varnish, Lacquer And Related Materials: Methods Of Inspection, Sampling And TestingThis standard elaborates the methods used to determine the physical and chemical properties of paint, varnish, lacquer, and related materials. The purpose of this standard is to establish standardized testing methodologies and to eliminate unnecessary or undesirable variations in test results when evaluating a product??s adherence to specification requirements. If any variation or modification of the methods established in this standard is required by any specification, the procedures listed in the specification will take precedence. Any conflict between this standard and any particular specification will be resolved in favor of the specification.

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METHOD 4252.1

March 22, 2001

2.5.1.2 Opaque specimens. For opaque specimens, the primary standard is a freshly prepared

layer of magnesium oxide of 0.5 mm minimum thickness identically irradiated and viewed.

2.5.2 Secondary standards. Secondary standards having spectral characteristics similar to those of

the test specimens should be used since the usual source-filter-photocell combinations only

approximate the CIE functions. Tristimulus values, X, Y, and Z for source C for master secondary

standards should be obtained according to manufacturer supplied software. Working standards

having nearly the same spectral character as a master standard should be calibrated by direct

photoelectric comparison of tristimulus values.

2.5.2.1 Transparent specimens. For transparent specimens, glass filters should be used as

secondary standards.

2.5.2.2 Opaque specimens. For opaque specimens, porcelain-enameled plaques known to be

reasonably permanent in color characteristics should be used repeatedly or impermanent materials

such as Munsell papers should be used and discarded frequently. The geometric conditions of

standardization for reflectance standards should be the same as those of the calorimeter.

3. DEFINITIONS

3.1 Color. An appearance characteristic of a specimen determined by the relative spectral

irradiance from the source, the relative spectral radiance factor of the specimen, and the spectral

tristimulus values of the CIE standard observer.

3.2 Relative luminance factor. The ratio of the luminance of a specimen for specified geometric

conditions of illumination and view to the luminance of a standard. If the luminance of the standard

is unity, the relative luminance factor is the tristimulus value, Y.

3.3 Tristimulus-filter set. A set of filters designed to provide receptor response functions for a

specified source approximating the spectral tristimulus values of the CIE standard observer for

source C.

4. PROCEDURE

4.1 Standard selection. Select a standard having spectral characteristics similar to those of the test

specimen.

4.2 Calorimeter. Set the calorimeter to read the values assigned to this standard based on

calibration relative to a primary standard.

4.3 Test specimen. Read the values of the test specimen.

4.4 Calculations.

4.4.1 Tristimulus values. Calculate the tristimulus values, X, Y, and Z, as prescribed in the

instructions for use of the calorimeter.

FED. TEST METHOD STD. 141D